It is well documented that the elderly and post-surgical patients are at a heightened risk of falling. These individuals are often afflicted by gait and balance disorders, weakness, dizziness, confusion, visual impairment, and postural hypotension (i.e., a sudden drop in blood pressure that causes dizziness and fainting), all of which are recognized as potential contributors to a fall. Additionally, cognitive and functional impairment, and sedating and psychoactive medications are also well recognized risk factors.
A fall places the patient at risk of various injuries including sprains, fractures, and broken bones—injuries which in some cases can be severe enough to eventually lead to a fatality. Of course, those most susceptible to falls are often those in the poorest general health and least likely to recover quickly from their injuries. In addition to the obvious physiological consequences of fall-related injuries, there are also a variety of adverse economic and legal consequences that include the actual cost of treating the victim and, in some cases, caretaker liability issues.
In the past, it has been commonplace to treat patients that are prone to falling by limiting their mobility through the use of restraints, the underlying theory being that if the patient is not free to move about, he or she will not be as likely to fall. However, research has shown that restraint-based patient treatment strategies are often more harmful than beneficial and should generally be avoided—the emphasis today being on the promotion of mobility rather than immobility. Among the more successful mobility-based strategies for fall prevention include interventions to improve patient strength and functional status, reduction of environmental hazards, and staff identification and monitoring of high-risk hospital patients and nursing home residents.
Additionally, and as is well known to those of ordinary skill in the art, patients are occasionally restrained for reasons not related to the likelihood of a fall including, for example, cases where the patient is unusually agitated or presents a threat to himself or herself, or to the staff.
However, patients who are physically restrained, though they might be protected against certain risks, are now at risk of death or other serious injury which can be brought about because of the circumstances of their confinement. For example, in a typical arrangement, a specialized poncho or vest which is slipped over the patient's head and their arms are extended through the openings provided. Then, straps which extend from the sides of the vest are threaded through slots in the front of the vest, after which the straps are securely tied to the bed frame or other stationary object. In some cases the back of the restraint device may have additional tie points for use with the straps provided or for use with other restraint device. Unfortunately, a patient who is agitated or deluded may slide through or climb over the bed railing and, because of the restraints, be held helpless above the ground unable to return to the bed. Asphyxiation, strangulation, or cardiac arrest can follow in short order.
Of course, if the patient is restrained within a wheelchair similar problems can arise. In some cases the patient can slip downward in the chair so that he or she is at least partially supported by the restraint straps that are tied to the chair frame and left suspended over the front of the chair. In other instances, the chair might tip over and the restraint will work to trap the patient underneath the chair.
It is well known that one proven method of reducing the incidence of injuries and deaths to restrained patients is careful monitoring by the caregiver. However, monitoring of high-risk patients, as effective as that care strategy might appear to be in theory, suffers from the obvious practical disadvantage of requiring additional staff if the monitoring is to be in the form of direct observation. Thus, the trend in patient monitoring has been toward the use of electrical devices to signal changes in a patient's circumstance to a caregiver who might be located either nearby or remotely at a central monitoring facility, such as a nurse's station. The obvious advantage of an electronic monitoring arrangement is that it frees the caregiver to pursue other tasks away from the patient. Additionally, when the monitoring is done at a central facility a single person can monitor multiple patients which can result in decreased staffing requirements.
Thus, what is needed is an electronic patient monitor that can be used to sense when a restrained patient may be in trouble and sound an alarm to summon a caregiver to his or her aid. Additionally, an automated method of sensing the orientation of the wheelchair is needed, so that if a wheelchair tips over an alarm sounds to notify a caregiver of the plight of the occupant.
General information relating to mat-type sensors, electronic monitors and other hardware for use in patient monitoring is relevant to the instant disclosure and may be found in U.S. Pat. Nos. 4,179,692, 4,295,133, 4,700,180, 5,600,108, 5,633,627, 5,640,145, and, 5,654,694, U.S. patent application Ser. Nos. 10/701,581 and 10/617,700, U.S. Pat. Nos. 6,111,509, 6,441,742, and 6,784,797 (the last three of which concern electronic monitors generally). Additional information may be found in U.S. Pat. Nos. 4,484,043, 4,565,910, 5,554,835, 5,623,760, 6,417,777, U.S. patent application 60/488,021, (sensor patents) and U.S. Pat. Nos. 5,065,727 and 6,065,727 (holsters for electronic monitors), the disclosures of all of which aforementioned patents are all incorporated herein by reference as if fully set out at this point. Further, U.S. Pat. No. 6,307,476 (discussing a sensing device which contains a validation circuit incorporated therein), U.S. Pat. No. 6,544,200, (for automatically configured electronic monitor alarm parameters), U.S. Pat. No. 6,696,653 (for a binary switch and a method of its manufacture), and U.S. patent application Ser. No. 10/125,059 (for a lighted splash guard) are similarly incorporated herein by reference.
Additionally, sensors other than mat-type pressure sensing switches may be used in patient monitoring including, without limitation, temperature sensors, patient activity sensors, patient location sensors, bed-exit sensors, toilet seat sensors (see, e.g., U.S. Pat. No. 5,945,914), wetness sensors (e.g., U.S. Pat. No. 6,292,102), decubitus ulcer sensors (e.g., U.S. Pat. No. 6,646,556), etc., all of which are incorporated herein by reference. Thus, in the text that follows the terms “mat” or “patient sensor” should be interpreted in its broadest sense to apply to any sort of patient monitoring switch or device, whether the sensor is pressure sensitive or not.
Finally, pending U.S. patent application Ser. No. 10/397,126, discusses how white noise can be used in the context of decubitus ulcer prevention and in other contexts, and U.S. Patent Application Ser. No. 60/543,718 teaches the use of medical feedback systems to reduce the risk of decubitus ulcer or pressure sore formation. Both of these references are similarly fully incorporated herein by reference.
Heretofore, as is well known in the patient monitoring arts, there has been a need for an invention to address and solve the above-described problems. Accordingly, it should now be recognized, as was recognized by the present inventors, that there exists, and has existed for some time, a very real need for such a system for monitoring patients.
Before proceeding to a description of the present invention, however, it should be noted and remembered that the description of the invention which follows, together with the accompanying drawings, should not be construed as limiting the invention to the examples (or preferred embodiments) shown and described. This is so because those skilled in the art to which the invention pertains will be able to devise other forms of this invention within the ambit of the appended claims.